The present invention relates to a method for manufacturing a semiconductor device which involves ion implantation and annealing steps for use in the manufacture of optical semiconductor devices.
Ion implantation is one possible means for changing a desired conductivity type to a compound semiconductor layer or providing therein a semi-insulating region. The ion implantation method is to implant ions of zinc, beryllium, or the like into a crystal-grown wafer. Since the ion implantation usually destroys crystals of the wafer, the ion implantation step must be followed by an annealing step for recovering the damage of crystals by heating the ion-implanted wafer.
The steps heretofore employed for implanting ions into and annealing an optical semiconductor encounter difficulty in precise control of the ion-implanted region and, in addition, have the defect of difficulty in selecting the material of the protective film or the necessity of using a special annealing equipment.